Music blared inside the Coliseum, and senior safety Kevin Ellison swayed from right to left.

He barked at his teammates, all of who were on the grass stretching.

Instead of warming up with his guys for the final home game of his career, Ellison had to watch.

And, it was his choice.

Doctors had cleared Ellison to play against Notre Dame, but after returning to the practice field for the first time since arthroscopic knee surgery, he halted his comeback.

"I couldn't be out there and not play like myself. I couldn't run on it the way I wanted to," he said. "It was hard, especially when you're cleared medically, to take yourself out and make that decision."

So Ellison watched and regrouped for his next shot to get back on the field.

Wednesday, Ellison took part in limited amounts of practice, working against the scout team before heading back inside for an ice bath and treatment.

"I'm hopeful that I react well to it. Last Tuesday, I felt good too, and the next day my knee was really sore," Ellison said. "I just want to make sure I'm smart about it and make sure that it's a gradual thing. I'm not trying to jump right into it."

Thursday morning will be crucial for Ellison if he wants to be on the field Saturday at the Rose Bowl when USC faces UCLA.

He said he'd head to bed optimistic that his knee would not swell and stiffen up like it did the previous week.

"Tomorrow's going to be the day," he said.

If Ellison wakes up and feels good, he'll come out to Howard Jones Field for more reps in preparation for the Bruins.

"I need the reps because I've been out four weeks," he said. "I need to get comfortable playing again and moving around. That's why I'm out there trying to get a feel for it."

USC head coach Pete Carroll said Ellison didn't look slow in his limited work on Wednesday.

"He did pretty well. He looked fast," Carroll said. "He took off on a couple of plays and pursued. He looked like he had fresh legs, too."

And so far, things appear to be pointed in the right direction, with Ellison coming off of a good practice.

"It was perfect," he said.

Taking criticism

It's pretty hard to find reasons to criticize the USC defense. The unit is holding opponents to fewer yards than any other team in the Bowl Subdivision.

Still, Carroll found one area where he wishes the team would do more - turnovers.

"This has not bee a great year for us with turnovers," he said. "Over the years, it'd be a below-average turnover year for us. Plus six is OK. I don't feel like it's great.

"We have not owned the football like we'd like to."

USC has forced 25 turnovers this season, tied for 33rd nationally. However, UCLA has turned the ball over 28 times this year - the 12th most in the nation.

UCLA quarterback Kevin Craft has been intercepted 19 times this season.

"We put pressure on every quarterback we play," cornerback Kevin Thomas said. "I assume the coaches are going to call this one similarly. We're going to try to pressure him and force him to make mistakes."

Last week against Arizona State, Craft saw three of his passes picked off and returned the other way for touchdowns. UCLA also had a fumble returned for a score by the Sun Devil defense.

This season, USC has had two defensive touchdowns - not enough.

"In years where we've played great defense, we've had five or six," Carroll said.

Thomas, who returned an interception for a score against Arizona State, said he hopes USC can add to that total Saturday.

"It's all about the ball. Every time we get our hands on the ball we try to score," he said. "Two's not enough. We need to get some more."

Extra Points

• USC offensive coordinator Steve Sarkisian would not comment on reports that said he's interviewed for the vacant head coaching position at Washington. Carroll wouldn't comment on if Washington has asked for permission to interview Sarkisian.

• Running back Stafon Johnson returned to practice Wednesday after sitting out one day with a deep thigh bruise.

"I'm just trying to get it going. It's still sore, but I was able to practice today," Johnson said. "That's a good thing. I'm able to bend it some more. I ran today. That's the big thing.

"I hate watching practice."

• Fullback Stanley Havili (ankle) did not practice, but reserve Adam Goodman returned to the field despite having knee surgery scheduled for Monday.

Carroll said Goodman could play with his injury and could be available Saturday.